What did the media report?
The media reported that drinking six to eight cups of coffee a day could reduce the risk of developing multiple sclerosis.
What did the research show?
The stories are based on a study carried out in mice by a group of international researchers from the US and Finland. The mice were induced to develop severe experimental autoimmune encephalomyelitis (EAE), an animal model of the condition MS.
They wanted to assess whether the action of a protein called CD73 was involved in the development of EAE in some of the mice. They found mice genetically engineered to lack the protein CD73 - it helps in the creation of a chemical called adenosine which suppresses the immune system - did not go on to develop EAE, while normal mice did.
Also as part of the laboratory experiments, the researchers tested what would happen when they blocked the CD73 signalling pathway in some normal mice by giving them 4mg per day of caffeine before being induced with EAE and for 20 to 30 days afterwards. These mice did not apparently develop EAE.
According to the authors, the caffeine stopped adenosine - one of the four building blocks in DNA - from binding to an adenosine receptor in mice. Adenosine is a common molecule in the human body and plays a vital part in the biochemical processes of sleep, suppression of arousal and energy transfer.
When adenosine could not bind to the receptor, this prevented certain T cells – white blood cells that play a central role in immune responses – from reaching the central nervous system and triggering the cascade of events that lead to EAE.
What did the researchers say?
‘This is an exciting and unexpected finding, and I think it could be important for the study of MS and other diseases,’ said study author Dr Linda Thompson, from the Oklahoma Medical Research Foundation. ‘A mouse is not a human being, so we can’t be sure caffeine will have the same effect on people prone to develop MS without much more testing.’
What does this mean for nursing practice?
Dr Lee Dunster, Head of Research at the MS Society, was cautious: ‘Over the years there have been numerous discoveries that have prevented EAE in mice but turning this into effective therapies for humans remains a challenge. Based on the results of this study, we wouldn’t advise people to change their caffeine intake.’
Proceedings of the National Academy of Sciences (2008) www.pnas.org